Snubbed spring group



June 29, 1954 c. v. PEARsoN SNUBBED SPRING GROUP Filed Sept. 29, 1950 INVENTOR. Zicaf Poya Patented June 29, 1954 SNUBBED SPRING GROUP Carl Victor Pearson, Chicago, Ill., assignor to American Steel Foundries, Chicago, Ill., a corporation of New Jersey Application September 29, 1950, Serial No. 187,458

14 Claims.

This invention rela-tes to spring groups and more particularly to a type incorporating a fric- 'tion unit.

The general `object of the invention is to provide a spring group having a friction unit of novel rugged construction which -will operate efficiently and have long life in service.

A more specific object of the invention is to devise a friction unit wherein the parts are stressed in compression in order to utilize the greatest strength characteristics of the device.

A further object of the invention is to provide a novel spring package wherein the friction device is designed to materially increase the strength of the top and bottom plates of the package.

A different object of the invention is to provide a friction unit wherein the parts lare arranged to accommodate lrelative movement between the top and bottom plates of the spring package without imposing excessive stresses such as cause failure of these pieces.

The invention comprehends a. friction unit wherein vertical and transverse relative movements between the top and bottom plates are resisted by friction developed along substantially horizontal surfaces.

These and other objects of the invention will become more apparent from the specification and the drawings wherein:i

Figure 1 is a top plan view of the novel spring package with the upper portion of one-half of the package removed to more clearly illustrate the construction of the bottom plate;

Figure 2 is a side elevational view of the novel package partly in section, the section being taken substantially on the line I2--2 of Figure 1;

vFigure 3 is an end view of the package partly in section, the section being taken substantially on the line 3--3 of Figure 2.

Describing the invention in detail, the spring package, which may be interposed between a side frame and a bolster of a railway car truck, comprises top and bottom `plates 2 and 4, confining at the four corners thereof therebetween coil springs 5. It will be understood that the spring package may be inverted so that the plate 2k may be at the bottom and the plate 4 at the top.

Each plate is provided with inwardly extending bosses 8, 8 for positioning the adjacent end of the related spring.

The bottom plate comprises an upstanding peripheral flange l which is disposed outwardly of the springs 6, for positioning the same and strengthening the bottom plate. Thev plate l4 has ay plurality of depending lugs I2, |25 which are adapted to interlock with an associated side frame or spring plank as will be readily understood by those skilled in the art. The plate 4 is provided on the top side thereof with a substantially centrally located friction member or fola lower generally designated I4, said member being preferably of skeletal construction and extending lengthwise transversely of the spring group between the sets of springs `I5, yfi at opposite ends of the group.

The friction member I4 comprises spaced upstanding side walls I6, I6 which at their lower ends are formed integral with the top side of the bottom spring plate 4, and at their upper ends are joined by a substantially horizontal web I8. The side walls I6, I6 are cored away at Il, II for good foundry practice and are interconnected by spaced end webs 20, 20 and intervening intermediate webs 22, 22. The bottom edges of the webs 2@ and 22 are formed integral with the top side of the bottom plate 4 and the upper edges merge with the web IB. It `will be readily appreciated that this box construction reinforces the bottom plate and provides an exceptionally rigid structure.

The top plate 2 Kcomprises a depending peripheral flange 26 which strengthens the top plate and also provides confining means for the upper ends of the springs B, 6. The plate `2 is formed centrally thereof .with a depending follower or housing generally indicated 28. The housing 28 telescopes over the friction member or bottom follower I4 and comprises spaced substantially vertical side walls 30, 30 which are interconnected at their lateral edges by spaced substantially vertical end walls 32, 32 to form a generally rectangular construction. It will be noted that the end walls 32, 32 are formed as continuations of ad- `jacent portions of the flange 26, thus forming a rigid structure. The side walls 3D, 30 extend alongside the side walls I6, I 6 of the bottom follower and are spaced a considerable distance outwardly therefrom. Similarly the walls 32, 32 eX- tend alongside the walls 20, 20 and are spaced a substantial distance outwardly therefrom. This feature permits relative rotational movement and canting movements between the top and bottom plates without any binding between the top and bottom followers.

The top side of the wall I8 of the bottom follower I 4 presents a substantially horizontal friction surface 34 which is engaged by the fiat bottom sides of center portions 3-6 of friction shoes generally indicated 38 disposed adjacent to opposite ends of the membe yI 4.

' follower 26.

Each shoe comprises ledges 40, 40 at opposite sides thereof formed integral with the lateral edges of the center portion 36 thereof. Each ledge 40 extends below the bottom side o-f the center portion 36 of the shoe and affords convenient positioning means for the shoe with respect to the member I4, the ledges 40, 40 extending downwardly at opposite sides of said member I4 and embracing the same. The upper extremities of the ledges 40, 40 project upwardly beyond the top side of the center portion 36 of the shoe, said upper portions of the ledges confining a combination spring plate and friction member 42 therebetween, said plate 42 straddling the shoes 38, 38 and seating on its bottom side as of 44, 44 against flat top surface of the center portions 36 of the shoes.

The spring plate 42 affords a seat adjacent each end above the related shoe 88 for the lower end of a substantially vertical compression spring 46, the upper end of each spring 46 being seated as at 48 against the under side of the top plate 2 and being positioned thereagainst by a depending boss 56 on the under side of said plate 2. The lower end of each actuating spring 46 may be positioned on the adjacent end of the plate by an upstanding boss 52 on the plate. It will be understood that the springs 46, 46 are under compression and urge the plate 42 against the shoes 38 which in turn are urged against the friction surface 34 on the bottom follower I4.

The ledges 46, 46 are formed on their opposite lateral edges with substantially parallel wedge faces 54, 54. The ledges 40, 4l) extend into diagonal slots 56 in the side walls 36, 36 of the top It will be noted that each ledge 46 is guided within the associated slot 56 by means of the surfaces 54, 54 which are engageable with complementary opposed surfaces 58, 58 at the lateral edges of the related slot. The surfaces 58, 58 are enlarged transversely of walls 30, 36 by continuing them on outwardly projecting flanges 60 formed on side walls 36, 30 around the margin of each slot 56. In operation, when the package is compressed the friction shoes 38, 38 are compelled, through a guiding engagement between surfaces 54 and 58, to move horizontally between the plate 42 and the top wall I8 of the bottom follower. Friction is also generated on the compression of the spring group between the outer surfaces 54 and 58. The friction increases in proportion to the compression of the spring group inasmuch as the springs 46, 46 form part of the load carrying coils. On expansion of the spring group, the coils 46, 46 expand urging the spring I plate 42 downwardly whereupon the shoes 46, y46 are caused to engage on their inner faces 54, 54 against the inner faces 58, 58 of the slots whereby the shoes are caused to move horizontally outwardly along surface 34 and the bottom of the spring seat plate 42.

It will be noted that the slots 56, 56 at opposite sides of follower 28 converge upwardly and that the surface 34 on the bottom follower is preferably horizontal although, of course, it could be angled from the horizontal, if desired, in order to produce different friction characteristics.

The top plate and the follower 28 are further reinforced by depending substantially vertical ribs 62, 62 which extend transversely of the side walls 3i), 3B, the inner ends of the ribs 62, 62 being connected to the external sides of the walls 36, and the outer ends merging into the adjacent portions of the top flange 26. The top edge of each rib 62 is formed integral with the bottom side of the top plate 2. Each rib 62 extends between the coils 6, 6 at the adjacent end of the spring package and forms positioning means therefor. The top plate has a plurality of upstanding positioning lugs 63, 63 which may enter complementary openings in a load carrying member such as a bolster.

The bottom plate is also further strengthened by substantially vertical gussets 64, 64 disposed between each set of coils at opposite ends of the group, each gusset 64 merging on its bottom side with the top side of the bottom plate and along its outer edge with an adjacent portion of the bottom fiange I6.

The package is held in assembly by a pair of nut and bolt assemblies 66, 66 which extend through outstanding lugs 68 and 'I6 formed on opposite ends of the plates 2 and 4. The head of each bolt is preferably welded as at I2 to the related lug 68 and bears against the top side thereof. The welding of the bolt head to lug 68 prevents the bolt from rattling when the package is in use and compressed. The shank of each bolt passes through aligned openings I4 and 'I6 in the related lugs 68 and lll, and it will be seen that the opening I6 is made substantially larger than the diameter of the shank of the bolt in order to permit relative canting and rotational movements between the top and bottom plates without stressing the bolt. The bottom of each bolt is provided with a nut 18 which supports a washer 80, the washer being adapted for abutment with the bottom side of the related lug 'I0 in order to limit expansion of the spring group. The nut and washer may be welded together as at 82 to prevent rattling and the nut may be tack welded as at 84 to the adjacent end of the bolt to prevent unthreading of the nut.

It will be noted that the gussets 62 and 64 join the flanges 26 in the area of the lugs 68 and 'l0 respectively, and thus reinforce this location. In addition, each lug 68 and 'IU is provided with a peripheral flange 86 which merges with the external side of the adjacent portion of the related flanges 26 or I0 of plates 2 or 4.

I claim:

1. In a friction device a pair of followers movable toward and away from each other, a friction area on one follower extending in a plane intersecting the axis of the device, a pair of shoes slidably engaging the area, co-operating guide means on the shoes and other follower disposed diagonally with respect to said area for moving said shoes toward and away from each other across said area in response to movement of said followers toward and away from each other, and means for urging said shoes against said area, the sides of said shoes engaging said area facing toward said one follower.

2. A friction device, according to claim l, wherein said friction area extends substantially perpendicular to the axis of the device.

3, A friction device, according to claim 1, wherein said shoes are disposed at opposite sides in the axis of the device and said guide means comprises substantially parallel opposed surfaces on the other follower and surfaces on each shoe received between the opposed surfaces.

4. In a friction device, followers movable toward and away from each other, a friction area on one follower extending substantially perpendicular to the axis of the device, a pair of shoes engaging said area, co-operating guide means on the shoes and other follower disposed diagonally with respect to said area for moving said shoes toward and away from eachY other across said area in response to movement of said followers toward and away from each other, said guide means comprisingA opposed surfaces on said other follower receiving portions of each shoe therebetween, and resilient means for urging said shoes against said area.

5. In a friction device a follower comprising a housing including spaced side walls and a pair of converging slots in each side wall, each slot presenting wedge surfaces on .opposed edges thereof.

6,. In a friction device, a follower, a friction member aligned with said follower axially of the device and presenting a friction area extending substantially perpendicular to the axis of the device, a pair of' shoes engaging on one of their sides said friction area and disposed at opposite sides of said axis, a tongue and groove interlock means between each shoe and said follower, each said interlock means incorporating slidably engaging surfaces on the follower and shoe, the surfaces on the follower and one shoe and the surfaces on the follower and other shoe diverging toward said area, a friction plate slidably engaging the opposite sides of said shoes, and spring means extending axially of the device and compressed between said plate and said follower.

7. In a friction device a pair of followers aligned axially of the device and movable toward and away from each other, one of said followers presenting a friction area facing the other, the other follower presenting opposed parallel surfaces at each side of the axis of the device, the surfaces at one side of the device converging with the surfaces on the opposite side of said axis in a direction away from said area, a shoe at each side of said device having a portion guidably received between the adjacent surfaces and engaging on a side thereof facing said one follower with said area, a friction member bearing against said shoes on the sides thereof facing said other follower, and spring means interposed between said other follower and said friction member to urge the latter against the shoes and said shoes against said area.

8. In a friction device a pair of telescopic followers, a friction area at the inner end of the inner follower extending transversely of the device, a pair of shoes at opposite sides of the device in diagonal face engagement with the other follower along surfaces converging toward the axis of the device, friction means engaging said shoes on the sides thereof opposite the first mentioned sides, and spring means reacting against said friction means and said other follower for urging said friction means into engagement with the shoes and the shoes against said friction area.

9. In a spring group top and bottom spring plates, coil springs connned therebetween, top and bottom telescoping followers between said plates and formed integral with respective plates, said bottom follower comprising a member having spaced side walls and a top web interconnecting the upper ends of the side walls, the lower ends of the side walls merging with the top side of said bottom plate, end and intermediate walls connecting said. side walls with each other and with said top web and the top side of said bottom plate, said top web presenting a substantially horizontal friction surface on the top side thereof, said top follower comprising a box-like casing having spaced side walls interconnected by spaced end walls at their lateral edges, the upper edges of saidv side walls and end walls of the top follower merging with the underside of said top plate, said side walls of the top follower being spaced a substantial distance from the side walls of the bottom follower and said end walls of the top follower being spaced a substantial distance from the end walls of the bottom follower whereby said followers are accommodated relative rotational and canting movement without binding, said top follower having transverse slots in each side wall disposed adjacent each end wall, the slots. in each side wall of the top follower converging upwardly and each presenting opposed guide areas extending diagonally with respect to the friction area, friction shoes in said top follower disposed adjacent opposite ends of said bottom follower and bearing on their bottom sides against said friction surface, each shoe having a pair of wings extending into the adjacent slots and having surfaces opposing the surfaces of the slot and substantially parallel therewith, each wing extending below the top side of the bottom follower to limit transverse movement of the associated shoe with respect to the bottom follower, a plate straddling both shoes and frictionally engaging the top sides thereof along substantially fiat areas, the wings of each shoe extending upwardly around the lateral edges of the plate to interlock therewih, and a compressed spring above each shoe seated at its lower end on the top side of the friction plate and at its upper end bearing against the bottom side of the top plate.

lo. In a spring group, spaced top and bottom spring plates, springs confined therebetween a follower formed integral with the top side of said bottom plate substantially centrally thereof and presenting a friction area on the top side thereof, a casing connected at its upper end with the top plate and telescoping adjacent to its lower end over the bottom follower, said casing having diagonal guide surfaces at opposite sides thereof, said surfaces converging toward the axis of said casing, friction shoe means received between said surfaces and in diagonal face engagement therewith, said surfaces being arranged to move said shoes during relative vertical movements bctween said follower and said casing across said friction area, a friction member engaging the top side of said shoes, and resilient means interposed between said top plate and said friction member.

'11. A spring plate comprising a plate member with a peripheral flange, a follower comprising a casing having spaced side walls and spaced end walls disposed in a substantially rectangular arrangement, all of said walls extending substantially perpendicular to said plate member and at one of their edges being formed integral with the interior side of said plate member, said end walls being formed at their inner extremities as continuations of said flange, said side walls having slots therein adjacent each end wall, each slot extending lengthwise at an angle to the adjacent end wall and presenting opposed substantially parallel guide surfaces.

l2. A spring plate, according to claim 1l, wherein said side walls are provided with outwardly extending flanges around the margins of said slots and said guide surfaces are continued on said flanges, and reinforcing ribs at opposite sides of said follower, each rib merging with the interior side of the plate member and at one of its ends with the exterior side of the adjacent side wall and at the other end with the interior side of the adjacent portion of the flange.

13. In a friction device, a pair of axially aligned followers, one follower presenting a friction surface, a pair of shoes engaging the surface along a common plane, and means for sliding the shoes toward and away from each other along the surface when said followers move toward and away from each other, said means comprising opposed substantially parallel faces on the other follower slidably receiving portions of the associated shoe therebetween, said faces extending axially of the device diagonally to the axis of the device.

14. In a friction device, a follower comprising surfaces converging and facing toward the axis of the device, said follower having converging faces facing away from the axis, a pair of spaced friction elements each having coaxial end portions guided between said surfaces and faces for engagement with said surfaces only during closure of the device and engagement with said faces only during expansion of the device, and resilient means interposed between said elements and said follower.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 793,661 Hitchcock July 4, 1905 869,754 Tower e Oct. 29, 1907 933,601 Tower Sept. 7, 1909 1,710,186 OConnor Apr. 23, 1929 1,809,908 Olander June 16, 1931 1,894,717 Sproul Jan. 17, 1933 2,295,548 Cottrell Sept. 15, 1942 2,356,743 Light Aug. 29, 1944 2,375,918 Haseltine May 15, 1945 2,431,375 Dath Nov. 25, 1947 

